Question

Which of the following would contain the largest number of moles?a.) All of answers contain the same number of moles.b.) 5.00 grams of chlorine (Cl)c.) 5.00 grams of copper (Cu)d.) 5.00 grams of calcium (Ca)e.) 5.00 grams of lithium (Li)

Answer 1

Answer:

The correct option is (e).

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$..[1]

For chlorine :

Given mass of chlorine = 5 g

Molar mass of chlorine = 35.5 g/mol

Putting values in equation 1, we get:

$\text{Moles of chlorine}=\frac{5 g}{35.5 g/mol}=0.1408 mol$

For copper :

Given mass of copper = 5 g

Molar mass of copper= 63.5 g/mol

Putting values in equation 1, we get:

$\text{Moles of copper}=\frac{5 g}{63.5 g/mol}=0.07874 mol$

For calcium :

Given mass of calcium= 5 g

Molar mass of calcium= 40 g/mol

Putting values in equation 1, we get:

$\text{Moles of calcium}=\frac{5 g}{40 g/mol}=0.125 mol$

For lithium :

Given mass of lithium= 5 g

Molar mass of lithium = 7 g/mol

Putting values in equation 1, we get:

$\text{Moles of lithium}=\frac{5 g}{7 g/mol}=0.7143 mol$

5 grams of lithium has highest number of moles.Hence, option (e) is correct.